The invention relates generally to communication across components in a conveyor system. More particularly, the invention relates to a technique for wireless mesh communication interconnecting components of a modular conveyor system.
Automation in manufacturing, shipping, and other applications often involves moving materials from one specialized work cell to another or to a final destination. Fixed material handling systems, such as conveyors, may route materials between cells. To facilitate the deployment of a fixed conveyor system, a system designer may purchase a conveyor system in multiple parts, known as “modules,” to be assembled on site. With the proper application of modules, a modular conveyor system can sort, manipulate, measure, and move materials between locations.
Each module of a modular conveyor system generally communicates with surrounding modules and a supervisory system. A module may communicate with an adjacent module to coordinate material movement to or from the adjacent module. Additionally, many material handling decisions may require a module to collect other information first from a supervisory system before executing the decision. A module may also communicate with a supervisory system to report a conveyor jam or to download a reconfiguration command.
Legacy communication schemes run discrete wires or cables from each module directly to a central controller and supervisory system. More recent communication schemes seek to avoid prohibitively expensive, complicated cabling by employing module-to-module wired communication. However, such a daisy-chain strategy often leads to extended repair cycles when a fault occurs in the cabling.
To avoid cabled communication in conveyor systems, wireless communication has been employed in a limited manner. As recently implemented, however, wireless communication schemes have relied either upon access point infrastructure or simple point-to-point connections for certain communications. However such solutions do not support a complete and truly modular wireless conveyor system topology, but instead support limited function including supervisory system connection, wireless operator controls, and diagnostic sensing. Moreover, if communication in a modular conveyor system were based on access point infrastructure the cost would be higher and the system would not be self-contained. If communication were based on simple point-to-point connections, the system would not be robust against communication disruptions.